In order to transmit payment card data or information other than the payment card data to a point of sale (POS) terminal, an electronic device may include a magnetic stripe transmission (MST) circuit. The MST circuit may generate magnetic stripe data by controlling the magnitude of a current flowing through a coil. The electronic device including the MST circuit may generate magnetic stripe data including payment-related information (e.g., payment card information) and may transmit the generated magnetic stripe data to a POS terminal located at a recognizable distance from the electronic device.
Typically, the maximum allowable current of a battery included in the electronic device is proportional to the capacity of the battery. In order to be normally driven, an existing MST circuit needs to be supplied with a current having a predetermined level or higher from the battery. However, there occurs a technical problem such that the capacity of a battery becomes smaller as the size of a portable electronic device becomes smaller, and accordingly, a maximum allowable current supplied from the battery may become smaller. As a result, when the capacity of the battery is small, the existing MST circuit may have difficulty in normally operating.
A magnetic-field near-field is determined according to the magnitude of a current flowing through a coil, the size of the coil, the inductance thereof, and the like. However, in terms of costs or the miniaturization of the electronic device, a large restriction exists in changing the magnitude of the current flowing through the coil or changing the size of the coil to be large. Also, the existing MST circuit is problematic in that, when the inductance of the existing MST circuit increases, a rise time period of the current of the existing MST circuit simultaneously increases and thus, an information recognition rate in the POS terminal is reduced.
Accordingly, there is a need for a low-current MST driving circuit that can normally operate in an electronic device (e.g., a wearable electronic device) having a low battery capacity. Also, there is a need for the MST circuit for improving a recognition rate without changing the magnitude of the current of the coil and the size of the coil.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.